Nucleosides with antiviral and anticancer activity

ABSTRACT

The invention provides a compound of formula I: 
     
       
         
         
             
             
         
       
     
     wherein R 1 -R 6  and X have any of the values described herein, as well as pharmaceutical compositions comprising such compounds and therapeutic methods comprising the administration of such compounds.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.14/336,225, filed Jul. 21, 2014, which is a continuation of U.S.application Ser. No. 14/229,292, filed on Mar. 28, 2014, which is acontinuation of U.S. application Ser. No. 13/753,252, filed on Jan. 29,2013, which issued as U.S. Pat. No. 8,765,935 on Jul. 1, 2014, which isa continuation of U.S. Ser. No. 11/721,325, filed on Aug. 18, 2009,which issued as U.S. Pat. No. 8,399,428 on Mar. 19, 2013, which is aNational Stage application of PCT/US2005/044442 filed on Dec. 8, 2005,and published as WO 2006/063149 on Jun. 15, 2006, which claims priorityto U.S. Provisional Application Ser. No. 60/634,677, filed on Dec. 9,2004, which applications and publications are incorporated by referenceherein in their entirety.

GOVERNMENT FUNDING

The invention described herein was made with U.S. Government supportunder grant CA 89615 awarded by the National Institutes of Health,National Cancer Institute. The United States Government has certainrights in the invention.

BACKGROUND OF THE INVENTION

Histidine triad enzymes are a superfamily of relatively small (MW 28-34Kda), homodimeric nucleoside monophosphate hydrolases and transferasescontaining an active site motif related to His-X-His-X-His-X-X, where Xis a hydrophobic amino acid (Bieganowski, P., et al., J. Biol. Chem.,2002, 277, 10852-10860). The HINT branch is the most ancient branch,having representatives in all forms of life (Bieganowski, P., et al., J.Biol. Chem., 2002, 277, 10852-10860; and Brenner. C., et al., NatureStruc. Biol., 1997, 4, 231-238).

The signature histidine triad residues were shown to be largelyresponsible for stabilizing binding to the phosphates, while the baseappeared to be sandwiched between two phenylalanines and an isoleucine(Brenner, C., et al., Nature Struc. Biol., 1997, 4, 231-238; and Lima,C. D., et al., Science, 1997, 278, 286-290). Further inspection revealedthat N-7 and O-4 for guanosine and N-7 and N-4 for adenosine are almostcompletely solvent exposed, while little, if any, specific bindinginteractions surrounding N-2 and N-3 were observed. Hydrogen bondinginteractions were observed between Asp-43 and both of the 2′- and3′-hydroxyl groups, which is consistent with the reduced ability of2′-deoxy nucleoside phosphoramidates to serve as substrates.

Although HINTs have been associated only recently with adenosinephosphoramidase activity, nucleoside phosphoramidase activity has beenobserved in partially purified extracts from rabbit liver, whole cellsand extracts of the human T-leukemia, CEM cells, peripheral bloodmononuclear cells (PBMCs) and green monkey Vero cells (Ledneva, R. K.,et al., 1970. Dokl. Akad. Nauk Sssr 193, 1308-10; Dudkin, S. M., et al.,1971, Febs 16, 48-50; Abraham. T. W., et al., 1996, J. Med. Chem. 39,4569-4575; Abraham, T. W., et al., 1997, Nucleosides Nucleotides 16,2079-2092; Chang, S.-L., et al., 2001, J. Med. Chem. 44, 223-231).

U.S. Pat. No. 6,475,985 reports certain specific nucleosidephosphoramidate analogs having anticancer and/or antiviral properties.There continues to be an interest in phosphoramidate nucleoside analogsdue to their demonstrated utility as prodrugs of antiviral andanticancer nucleoside monophosphates, or pronucleotides (McGuigan, C.,et al., 1993. Bioorg. Med. Chem. Lett. 3, 1207-1210; Balzarini, J., etal., 1996, Mol. Pharmacol. 50, 1207-1213; Chang, S. L., et al., 2000,Nucleosides, Nucleotides & Nucleic Acids 19, 87-100; Kim, J., Drontle,et al., 2004. Nucleos. Nucleot. Nucleic Acids 23, 483-493; and Klein, M.G., et al., 1998, Exp. Cell. Res. 244, 26-32).

In spite of the above reports, there is currently a need forchemotherapeutic agents with antiviral and or anticancer properties. Inparticular there is a need for agents that are selectively activated atthe sight of a disease or virus.

SUMMARY OF THE INVENTION

Although, the nature of the enzyme responsible for phosphoramidatehydrolysis has not been determined, direct evidence of intracellular P—Nbond hydrolysis by a putative phosphoramidase was demonstrated bystudies of the intracellular metabolism of fluorodeoxyuridinephosphoramidates with permeablized cells and O¹⁸ labeled AZT tryptophanmethyl ester phosphoramidate with capillary LC-ESI-MS/MS.

Recently, hHINT1 has been isolated and cloned by a combination ofaffinity chromatography and T7 phage display a human phosphoramidase.Early studies have demonstrated that the enzyme will efficientlyhydrolyze guanosine, adenosine and to a limited extent uridine andcytosine phosphoramidates containing primary amines. hHINT1 has beenshown to be over-expressed in breast, lung and ovarian cancer tissuesrelative to normal tissues. Recently, it has been shown that humanbreast cancer has at least 6-times more expressed hHINT1 activity thannormal breast tissues. In addition, it is known that the hHINT1 isoverexpressed in the liver and brain. Consequently, antiviral oranticancer phosphoramidates that are substrates for hHINTs shouldfacilitate the design of tissue specific antiviral and anticancerphosphoramidate based therapeutics.

Inspection of the active site of hHINT1 has revealed that hydrogenbonding, ion pairing or polar interactions at the 2′- and 3′-positionspreferentially interact with the active site residue Asp-43, which isconsistent with the reduced ability of 2′-deoxy nucleosidephosphoramidates to serve as substrates. In addition, phosphoramidateswith a D-amino acid are hydrolyzed at least 20-fold more efficientlythan phosphoramidates containing L-amino acids. Consequently, compoundscontaining 1) an electropositive group at the 2′-position, and/or 2) agroup having a stereochemistry that corresponds to that of an N-linkedD-amino acid on the phosphorous are especially good substrates forhHINT1.

The present invention provides compounds that act as antiviral and oranticancer agents. Accordingly there is provided a compound of theinvention which is a compound of formula I:

wherein:

R₁ is adenine, guanine, cytosine, thymine, 3-deazaadenine, or uracil,optionally substituted by 1, 2, or 3 U; wherein each U is independentlyhalo, hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, (C₁-C₆)alkoxy,(C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl, (C₁-C₆)alkanoyloxy,trifluoromethyl, hydroxy(C₁-C₆)alkyl, —(CH₂)₁₋₄P(═O)(OR_(w))₂ aryl,aryl(C₁-C₆)alkyl, or NR_(x)R_(y):

R₂ and R₆ are each independently hydrogen, halo, hydroxy, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, (C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano,—N(R_(z))C(═O)N(R_(aa))(R_(ab)). —N(R_(z))C(═O)OR_(ac), orNR_(ad)R_(ae), provided that one of R₂ and R₆ is hydroxy halo,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, trifluoromethyl, cyano, orNR_(ad)R_(ae);

R₃ is hydrogen, halo, hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano,—N(R_(z))C(═O)N(R_(aa))(R_(ab)), —N(R_(z))C(═O)OR_(ac), orNR_(ad)R_(ae);

R₄ is hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, aryl, aryl(C₁-C₆)alkyl,or 2-cyanoethyl;

R₅ is an amino acid, a peptide, or NR_(a) R_(b);

R₇ is hydrogen, halo, hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano,—N(R_(z))C(═O)N(R_(aa))(R_(ab)), —N(R_(z))C(═O)OR_(ac), orNR_(ad)R_(ae);

X is oxy, thio, or methylene;

each R_(a) and R_(b) is independently hydrogen, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, aryl, or Het; or R_(a) and R_(b) together with thenitrogen to which they are attached form a nitrogen-linked Het;

each R_(w) is independently hydrogen or (C₁-C₆)alkyl;

R_(x) and R_(y) are each independently hydrogen, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, phenyl, benzyl, phenethyl, or (C₁-C₆)alkanoyl; orR_(x) and R_(y) together with the nitrogen to which they are attachedare pyrrolidino, piperidino or morpholino;

R_(z) is hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl, orphenethyl;

R_(aa) and R_(ab) are each independently hydrogen, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, phenyl, benzyl, or phenethyl; or R_(aa) and R_(ab)together with the nitrogen to which they are attached are pyrrolidino,piperidino or morpholino;

R_(ac) is hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl, orphenethyl;

R_(ad) is hydrogen (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl, orphenethyl;

R_(ae) is hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl, orphenethyl;

wherein any (C₁-C₆)alkyl of R₁-R₇, R_(a), R_(b), R_(w), R_(x), R_(y),R_(z), R_(a), R_(ab), R_(ac), R_(ad), and R_(ae) is optionallysubstituted with one or more (e.g. 1, 2, 3, or 4) halo, hydroxy,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano, oxo (═O),(C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, (C₃-C₆)cycloalkyl(C₁-C₆)alkyl,(C₁-C₆)alkyl-S—(C₁-C₆)alkyl-, aryl, Het, aryl(C₁-C₆)alkyl, orHet(C₁-C₆)alkyl, or NR_(aj)R_(ak); wherein each R_(aj) and R_(ak) isindependently hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl,or phenethyl;

and wherein any aryl or Het may optionally be substituted with one ormore substituents selected from the group consisting of halo, hydroxy,(C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, (C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy,(C₁-C₆)alkanoyl, (C₁-C₆)alkanoyloxy, trifluoromethyl, trifluoromethoxy,nitro, cyano, and amino;

or a pharmaceutically acceptable salt thereof. In one embodiment theinvention provides a compound of formula (I); provided that R₂ and R₃are each not hydroxy when R₁ is adenine, guanine, cytosine, thymine, oruracil, X is oxy, R₅ is an amino acid or a peptide; R₆ is hydrogen, andR₇ is hydrogen; and; provided R₁ is not 3-deazaadenine, when R₂ ishydroxy; R₃ is hydroxy; R₄ is hydrogen; R₅ a nitrogen linked radical offormula III;

wherein R_(h) is benzyl or 3-indolylmethyl; and R_(j) is methyl; x isoxy, R₆ is hydrogen, and R₇ is hydrogen.

The invention also provides a method for treating a viral infection inan animal comprising administering an effective amount of a compound offormula I or a pharmaceutically acceptable salt thereof to an animal(e.g. a mammal) in need of such treatment.

The invention also provides a method for treating HCV in an animalcomprising administering an effective amount of a compound of formula Ior a pharmaceutically acceptable salt thereof to an animal in need ofsuch treatment.

The invention also provides a method for treating a metabolic liverdisorder (e.g. hemochromatosis, cirrohsis, Wilson's disease, biliaryatresia, hepatitis, or any other genetic or environmentally inducedliver disease) in an animal comprising administering an effective amountof a compound of formula I or a pharmaceutically acceptable salt thereofto an animal in need of such treatment.

The invention also provides a method for treating a cancer in the liverof an animal comprising administering an effective amount of a compoundof formula I or a pharmaceutically acceptable salt thereof to an animalin need of such treatment.

The invention also provides a method for treating cancer in the brain ofan animal comprising administering an effective amount of a compound offormula I or a pharmaceutically acceptable salt thereof to an animal inneed of such treatment.

The invention also provides a method for treating breast cancer, lungcancer or ovarian cancer in an animal comprising administering aneffective amount of a compound of formula I or a pharmaceuticallyacceptable salt thereof to an animal in need of such treatment.

The invention also provides the use of a compound of formula I or apharmaceutically acceptable salt thereof to prepare a medicament fortreating a viral infection in a mammal.

The invention also provides the use of a compound of formula I or apharmaceutically acceptable salt thereof to prepare a medicament fortreating HCV in a mammal.

The invention also provides the use of a compound of formula I or apharmaceutically acceptable salt thereof to prepare a medicament fortreating a metabolic liver disorder in a mammal.

The invention also provides the use of a compound of formula I or apharmaceutically acceptable salt thereof to prepare a medicament fortreating a cancer in the liver of a mammal.

The invention also provides the use of a compound of formula I or apharmaceutically acceptable salt thereof to prepare a medicament fortreating cancer in the brain of a mammal.

The invention also provides the use of a compound of formula I or apharmaceutically acceptable salt thereof to prepare a medicament usefulfor treating breast cancer, lung cancer or ovarian cancer in a mammal.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 Illustrates the synthesis of representative compounds of theinvention.

FIG. 2 Illustrates starting materials useful for preparing compounds ofthe invention.

FIG. 3 Illustrates compounds useful in the methods of the invention.

FIG. 4 Illustrates the preparation of compounds of the invention.

DETAILED DESCRIPTION

The following definitions are used, unless otherwise described: halo isfluoro, chloro, bromo, or iodo. Alkyl, alkoxy. etc. denote both straightand branched groups; but reference to an individual radical such as“propyl” embraces only the straight chain radical, a branched chainisomer such as “isopropyl” being specifically referred to. Aryl denotesa phenyl radical or an ortho-fused bicyclic carbocyclic radical havingabout nine to ten ring atoms in which at least one ring is aromatic. Hetencompasses a radical of a monocyclic, bicyclic, or tricyclic ringsystem containing a total of 3-20 atoms, including one or more (e.g., 1,2, 3, 4, 5, or 6) carbon atoms, and one or more (e.g., 1, 2, 3, or 4)heteroatoms selected from oxygen, sulfur, and N(X) wherein X is absentor is H, O, (C₁-C₄)alkyl, phenyl or benzyl, wherein one or more ringcarbons of Het can optionally be substituted with oxo (═O); Heteroarylencompasses a radical attached via a ring carbon of a monocyclicaromatic ring containing five or six ring atoms consisting of carbon andone to four heteroatoms each selected from the group consisting ofnon-peroxide oxygen, sulfur, and N(X) wherein X is absent or is H, O,(C₁-C₄)alkyl, phenyl or benzyl, as well as a radical of an ortho-fusedbicyclic heterocycle of about eight to ten ring atoms derived therefrom,particularly a benz-derivative or one derived by fusing a propylene,trimethylene, or tetramethylene diradical thereto. The term Hetencompasses Heteroaryl.

The term “amino acid,” comprises the residues of the natural amino acids(e.g. Ala, Arg, Asn, Asp, Cys, Glu, Gin, Gly, His, Hyl, Hyp, Ile, Leu,Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr, and Val) in D or L form, as wellas unnatural amino acids (e.g. phosphoserine, phosphothreonine,phosphotyrosine, hydroxyproline, gamma-carboxyglutamate; hippuric acid,octahydroindole-2-carboxylic acid, statine,1,2,3,4,-tetrahydroisoquinoline-3-carboxylic acid, penicillamine,ornithine, citruline, α-methyl-alanine, para-benzoylphenylalanine,phenylglycine, propargylglycine, sarcosine, and tert-butylglycine). Theterm also comprises natural and unnatural amino acids protected at thecarboxy terminus (e.g. as a (C₁-C₆)alkyl, phenyl or benzyl ester or asan amide, such as for example, a mono-(C₁-C₆)alkyl or di-(C₁-C₆)alkylamide. Other suitable carboxy protecting groups are known to thoseskilled in the art (See for example, T. W. Greene. Protecting Groups InOrganic Synthesis; Wiley: New York, 1981, and references cited therein).An amino acid can be linked to the remainder of a compound of theinvention through the carboxy terminus, the amino terminus, or throughany other convenient point of attachment. Preferably, when R₅ is anamino acid, the amino acid is linked to phosphorous through the aminonitrogen, forming a phosphoramidate. The term animal includes birds,reptiles and mammals. In one specific embodiment of the invention theanimal is a human.

The term “peptide” describes a sequence of 2 to 25 amino acids (e.g. asdefined hereinabove) or peptidyl residues. The sequence may be linear orcyclic. A peptide can be linked to the remainder of a compound offormula I through the carboxy terminus, the amino terminus, or throughany other convenient point of attachment. Preferably a peptide comprises2 to 25, or 5 to 20 amino acids. Peptide derivatives can be preparedusing techniques that are well known in the art, for example, usingsolid phase peptide synthesis techniques. In one embodiment, when R₅ isa peptide, the peptide is linked to phosphorous through the N-terminalnitrogen, forming a phosphoramidate. In another embodiment, when R₅ is apeptide, the peptide is linked to phosphorous through the N-terminalnitrogen, forming a phosphoramidate, and the carbon adjacent to theN-terminal nitrogen has the configuration of a D-amino acid.

The term “viral infection” includes human immunodeficiency virus (HIV),herpes simplex virus-2 (HSV-2), varicellazoster, vaccinia, humancytomegalovirus, ebola, hepatitis B (HBV), hepatitis C (HCV) and thelike.

It will be appreciated by those skilled in the art that compounds of theinvention having a chiral center may exist in and be isolated inoptically active and racemic forms. Some compounds may exhibitpolymorphism. It is to be understood that the present inventionencompasses any racemic, optically-active, polymorphic, orstereoisomeric form, or mixtures thereof, of a compound of theinvention, which possess the useful properties described herein, itbeing well known in the art how to prepare optically active forms (forexample, by resolution of the racemic form by recrystallizationtechniques, by synthesis from optically-active starting materials, bychiral synthesis, or by chromatographic separation using a chiralstationary phase) and how to determine antiviral activity using thestandard tests described herein, or using other similar tests which arewell known in the art.

Specific values listed below for radicals, substituents, and ranges, arefor illustration only; they do not exclude other defined values or othervalues within defined ranges for the radicals and substituents

Specifically, (C₁-C₆)alkyl can be methyl, ethyl, propyl, isopropyl,butyl, iso-butyl, sec-butyl, pentyl, 3-pentyl, or hexyl;(C₃-C₆)cycloalkyl can be cyclopropyl, cyclobutyl, cyclopentyl, orcyclohexyl; (C₃-C₆)cycloalkyl(C₁-C₆)alkyl can be cyclopropylmethyl,cyclobutylmethyl, cyclopentylmethyl, cyclohexylmethyl,2-cyclopropylethyl, 2-cyclobutylethyl, 2-cyclopentylethyl, or2-cyclohexylethyl; (C₁-C₆)alkoxy can be methoxy, ethoxy, propoxy,isopropoxy, butoxy, iso-butoxy, sec-butoxy, pentoxy, 3-pentoxy, orhexyloxy; (C₁-C₆)alkanoyl can be acetyl, propanoyl or butanoyl;hydroxy(C₁-C₆)alkyl can be hydroxymethyl, 1-hydroxyethyl,2-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl, 3-hydroxypropyl,1-hydroxybutyl, 4-hydroxybutyl, 1-hydroxypentyl, 5-hydroxypentyl,1-hydroxyhexyl, or 6-hydroxyhexyl; (C₂-C₆)alkanoyloxy can be acetoxy,propanoyloxy, butanoyloxy, isobutanoyloxy, pentanoyloxy, or hexanoyloxy;aryl can be phenyl, indenyl, or naphthyl; and heteroaryl can be furyl,imidazolyl, triazolyl, triazinyl, oxazoyl, isoxazoyl thiazolylisothiazoyl, pyrazolyl, pyrrolyl, pyrazinyl, tetrazolyl, pyridyl, (orits N-oxide), thienyl, pyrimidinyl (or its N-oxide), indolyl,isoquinolyl (or its N-oxide) or quinolyl (or its N-oxide).

A specific value for R_(a) is (C₁-C₆)alkyl optionally substituted withone or more halo, hydroxy, (C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy,(C₁-C₆)alkanoyl, (C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano,(C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, (C₃-C₆)cycloalkyl(C₁-C₆)alkyl,(C₁-C₆)alkyl-S—(C₁-C₆)alkyl-, aryl, Het, aryl(C₁-C₆)alkyl, orHet(C₁-C₆)alkyl, or NR_(aj)R_(ak); wherein each R_(aj) and R_(ak) isindependently hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl,or phenethyl.

A specific value for R_(a) is (C₁-C₆)alkyl optionally substituted withone or more halo, hydroxy, (C₁-C₆)alkoxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, cyano, aryl, or Het.

A specific value for R_(a) is (C₁-C₆)alkyl optionally substituted withone or more aryl or Het.

A specific value for R_(a) is (C₁-C₆)alkyl substituted with a phenyl,naphthyl, pyridyl, indolyl, isoindolyl, furyl, thienyl, pyrrolyl,benzofuranyl, benzothienyl, imidazolyl, thiazoyl, pyrrolidinyl,piperidinyl, piperazinyl, or morpholino ring, which ring is optionallysubstituted with one or more substituents selected from the groupconsisting of halo, hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, trifluoromethoxy, nitro, cyano, andamino.

A specific value for R_(a) is (C₁-C₆)alkyl substituted with a phenyl orindolyl ring, which ring is optionally substituted with one or moresubstituents selected from the group consisting of halo, hydroxy,(C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, (C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy,(C₁-C₆)alkanoyl, (C₁-C₆)alkanoyloxy, trifluoromethyl, trifluoromethoxy,nitro, cyano, and amino.

A specific value for R_(a) is (C₁-C₆)alkyl substituted with a phenylring.

A specific value for R_(a) is (C₁-C₆)alkyl substituted with an indolylring.

A specific value for R_(a) is phenylmethyl, phenethyl, indolylmethyl, or2-indolylethyl.

A specific value for R_(a) is 2-indol-3-ylethyl.

A specific value for R_(b) is hydrogen.

A specific compound of formula (I) has the formula R₅—B, wherein B is aphosphorous-linked 9-beta-D-arabinofuranosyladenosine monophosphate,9-beta-D-arabinofuranosylguanosine monophosphate, or9-beta-D-arabinofuranosylcytosine monophosphate and wherein R₅ has anyof the values defined herein.

A specific value for R₅ is NR_(a)R_(b) wherein R_(a) is2-indol-3-ylethyl; and R_(b) is hydrogen.

A specific value for R₁ is guanine, cytosine, thymine, 3-deazaadenine,or uracil optionally substituted by 1, 2, or 3 U; wherein each U isindependently halo, hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, hydroxy(C₁-C₆)alkyl,—(CH₂)₁₋₄P(═O)(OR_(w))₂ aryl, aryl(C₁-C₆)alkyl, or NR_(x)R_(y).

A specific value for R₁ is adenine, cytosine, thymine, 3-deazaadenine,or uracil, optionally substituted by 1, 2, or 3 U; wherein each U isindependently halo, hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, hydroxy(C₁-C₆)alkyl,—(CH₂)₁₋₄P(═O)(OR_(w))₂ aryl, aryl(C₁-C₆)alkyl, or NR_(x)R_(y).

A specific value for R₁ is adenine, guanine, cytosine, thymine, oruracil optionally substituted by 1, 2, or 3 U; wherein each U isindependently halo, hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, hydroxy(C₁-C₆)alkyl,—(CH₂)₁₋₄P(═O)(OR_(w))₂ aryl, aryl(C₁-C₆)alkyl, or _(NrxRy).

A specific value for R₁ is cytosine, thymine, 3-deazaadenine, or uracil,optionally substituted by 1, 2, or 3 U; wherein each U is independentlyhalo, hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, (C₁-C₆)alkoxy,(C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl, (C₁-C₆)alkanoyloxy,trifluoromethyl hydroxy(C₁-C₆)alkyl, —(CH₂)₁₋₄P(═O)(OR_(w))₂ aryl,aryl(C₁-C₆)alkyl, or _(NrxRy).

A specific value for R₁ is 3-deazaadenine optionally substituted by 1,2, or 3 U; wherein each U is independently halo, hydroxy, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, (C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, hydroxy(C₁-C₆)alkyl,—(CH₂)₁₋₄P(═O)(OR_(w))₂ aryl, aryl(C₁-C₆)alkyl, or NR_(x)R_(y).

A specific value for R₁ is adenine, guanine, cytosine, thymine,3-deazaadenine, or uracil.

A specific value for R₁ is guanine, cytosine, thymine, 3-deazaadenine,or uracil.

A specific value for R₁ is cytosine, thymine, 3-deazaadenine, or uracil.

A specific value for R₁ is cytosine, thymine, or uracil.

A specific value for R₁ is a nitrogen linked radical of formula VI:

wherein R_(af) is hydrogen, halo, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, ortrifluoromethyl; and R_(ag) is hydrogen, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, trifluoromethyl, hydroxy(C₁-C₆)alkyl, or—(CH₂)₁₋₄P(═O)(OR_(w))₂.

A specific value for R₂ is hydroxy.

A specific value for R₂ is halo.

A specific value for R₂ is fluoro.

A specific value for R₂ is chloro.

A specific value for R₂ is (C₁-C₆)alkoxy.

A specific value for R₂ is methoxy.

A specific value for R₂ trifluoromethyl.

A specific value for R₂ is cyano.

A specific value for R₂ is amino, methylamino, dimethylamino,ethylamino, or dimethylamino.

A specific value for R₃ is hydroxy.

A specific value for R₃ is hydrogen.

A specific value for R₃ is halo.

A specific value for R₃ is fluoro.

A specific value for R₃ is chloro.

A specific value for R₃ is trifluoromethyl.

A specific value for R₃ is azido

A specific value for R₃ is cyano.

A specific value for R₃ is amino, methylamino, dimethylamino,ethylamino, or dimethylamino.

A specific value for R₄ is hydrogen.

A specific value for R₄ is methyl or ethyl.

A specific value for R₄ is 2-cyanoethyl.

A specific value for R₅ is an amino acid.

A specific value for R₅ is a peptide.

A specific value for R₅ is a nitrogen linked radical of formula II:

wherein:

R_(h) is hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl,(C₃-C₆)cycloalkyl(C₁-C₆)alkyl, (C₁-C₆)alkyl-S—(C₁-C₆)alkyl-, aryl,heteroaryl, aryl(C₁-C₆)alkyl, or heteroaryl(C₁-C₆)alkyl; wherein anyaryl or heteroaryl may optionally be substituted with 1, 2, or 3 Z;

each Z is independently halo, hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, trifluoromethoxy, nitro, cyano, oramino; and

R_(k) is hydrogen or (C₁-C₆)alkyl that is optionally substituted withone or more (e.g. 1, 2, 3, or 4) halo, hydroxy, (C₁-C₆)alkoxy,(C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl, (C₁-C₆)alkanoyloxy,trifluoromethyl, azido, cyano, oxo (═O) or NR_(ad)R_(ae). A specificvalue for R_(k) is (C₁-C₅)alkyl optionally substituted with one or more(e.g. 1, 2, 3, or 4) halo, hydroxy, (C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy,(C₁-C₆)alkanoyl, (C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano, oxo(═O) or NR_(ad)R_(ae).

A specific value for R_(h) is hydrogen, (C₁-C₆)alkyl, phenylmethyl, or3-indolylmethyl.

A specific value for R_(h) is phenylmethyl.

A specific value for R_(h) is 3-indolylmethyl.

A specific compound is a compound wherein the carbon bearing R_(h) hasthe (R) absolute configuration.

A specific value for R₅ is a nitrogen linked radical of formula III:

wherein R_(h) is hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl,(C₃-C₆)cycloalkyl(C₁-C₆)alkyl, (C₁-C₆)alkyl-S—(C₁-C₆)alkyl-, aryl,heteroaryl, aryl(C₁-C₆)alkyl, or heteroaryl(C₁-C₆)alkyl; wherein anyaryl or heteroaryl may optionally be substituted with 1, 2, or 3 Z;R_(j) is hydrogen, (C₁-C₆)alkyl, phenyl, benzyl, or phenethyl; andwherein each Z is independently halo, hydroxy, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, (C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, trifluoromethoxy, nitro, cyano, oramino.

A specific value for R_(h) is hydrogen, (C₁-C₆)alkyl, phenylmethyl, or3-indolylmethyl.

A specific value for R_(h) is phenylmethyl.

A specific value for R_(h) is 3-indolylmethyl.

A specific value for R₆ is hydrogen or (C₁-C₆)alkyl.

A specific value for R₂ is hydrogen or alkyl; and R₆ is halo, hydroxy,(C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, (C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy,(C₁-C₆)alkanoyl, (C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano,—N(R_(z))C(═O)N(R_(aa))(R_(ab)), —N(R_(z))C(═O)OR_(ac), orNR_(ad)R_(ae).

A specific value for R₇ is hydrogen or (C₁-C₆)alkyl.

A specific compound is a compound wherein R₃ is hydrogen or alkyl; andR₇ is halo, hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, (C₁-C₆)alkoxy,(C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl, (C₁-C₆)alkanoyloxy,trifluoromethyl, azido, cyano, —N(R_(z))C(═O)N(R_(aa))(R_(ab)),—N(R_(z))C(═O)OR_(ac), or NR_(ad)R_(ae);

A specific compound is(2-(3-indolyl)-1(R)-methylcarbamoylethyl)-phosphoramidic acid mono(1-B-arabinofuranosyladenosine)ester; or a pharmaceutically acceptablesalt thereof.

In one specific embodiment the invention provides a compound of formulaI:

wherein:

R₁ is adenine, guanine, cytosine, thymine, 3-deazaadenine, or uracil,optionally substituted by 1, 2, or 3 U; wherein each U is independentlyhalo, hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, (C₁-C₆)alkoxy,(C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl, (C₁-C₆)alkanoyloxy,trifluoromethyl, hydroxy(C₁-C₆)alkyl, —(CH₂)₁₋₄P(═O)(OR_(w))₂ aryl,aryl(C₁-C₆)alkyl, or NR_(x)R_(y);

R₂ and R₆ are each independently hydrogen, halo, hydroxy, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, (C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano,—N(R_(z))C(═O)N(R_(aa))(R_(ab)), —N(R_(z))C(═O)OR_(ac), orNR_(ad)R_(ae), provided that one of R₂ and R₆ is hydroxy halo,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, trifluoromethyl, cyano, orNR_(ad)R_(ae);

R₃ is hydrogen, halo, hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano,—N(R_(z))C(═O)N(R_(aa))(R_(ab)), —N(R_(z))C(═O)OR_(ac), orNR_(ad)R_(ae);

R₄ is hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, aryl, aryl(C₁-C₆)alkyl,or 2-cyanoethyl:

R₅ is NR_(a) R_(b);

R₇ is hydrogen, halo, hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano,—N(R_(z))C(═O)N(R_(aa))(R_(ab)), —N(R_(z))C(═O)OR_(ac), orNR_(ad)R_(ae);

X is oxy, thio, or methylene;

each R_(a) and R_(b) is independently hydrogen, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, aryl, or Het; or R_(a) and R_(b) together with thenitrogen to which they are attached form a nitrogen-linked Het;

each R_(w) is independently hydrogen or (C₁-C₆)alkyl;

R_(x) and R_(y) are each independently hydrogen, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, phenyl, benzyl, phenethyl, or (C₁-C₆)alkanoyl; orR_(x) and R_(y) together with the nitrogen to which they are attachedare pyrrolidino, piperidino or morpholino;

R_(z) is hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl, orphenethyl;

R_(aa) and R_(ab) are each independently hydrogen, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, phenyl, benzyl, or phenethyl; or R_(aa) and R_(ab)together with the nitrogen to which they are attached are pyrrolidino,piperidino or morpholino;

R_(ac) is hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl, orphenethyl;

R_(ad) is hydrogen (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl, orphenethyl;

R_(ae) is hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl, orphenethyl;

wherein any (C₁-C₆)alkyl of R₁-R₇, R_(a), R_(b), R_(w), R_(x), R_(y),R_(z), R_(aa), R_(ab), R_(ae), R_(ad), and R_(ae), is optionallysubstituted with one or more (e.g. 1, 2, 3, or 4) halo, hydroxy,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano, oxo (═O),(C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, (C₃-C₆)cycloalkyl(C₁-C₆)alkyl,(C₁-C₆)alkyl-S—(C₁-C₆)alkyl-, aryl, Het, aryl(C₁-C₆)alkyl, orHet(C₁-C₆)alkyl, or NR_(aj)R_(ak); wherein each R_(aj) and R_(ak) isindependently hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl,or phenethyl;

and wherein any aryl or Het may optionally be substituted with one ormore substituents selected from the group consisting of halo, hydroxy,(C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, (C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy,(C₁-C₆)alkanoyl, (C₁-C₆)alkanoyloxy, trifluoromethyl, trifluoromethoxy,nitro, cyano, and amino;

or a pharmaceutically acceptable salt thereof.

In one specific embodiment the invention provides a compound of formulaI:

wherein:

R₁ is adenine, guanine, cytosine, thymine, 3-deazaadenine, or uracil,optionally substituted by 1, 2, or 3 U; wherein each U is independentlyhalo, hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, (C₁-C₆)alkoxy,(C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl, (C₁-C₆)alkanoyloxy,trifluoromethyl, hydroxy(C₁-C₆)alkyl, —(CH₂)₁₋₄P(═O)(OR_(w))₂ aryl,aryl(C₁-C₆)alkyl, or NR_(x)R_(y);

R₂ and R₆ are each independently hydrogen, halo, hydroxy, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, (C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano,—N(R_(z))C(═O)N(R_(aa))(R_(ab)), —N(R_(z))C(═O)OR_(ac), orNR_(ad)R_(ae), provided that one of R₂ and R₆ is hydroxy halo,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, trifluoromethyl, cyano, orNR_(ad)R_(ae);

R₃ is hydrogen, halo, hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano,—N(R_(z))C(═O)N(R_(aa))(R_(ab)), —N(R_(z))C(═O)OR_(ac), orNR_(ad)R_(ae);

R₄ is hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, aryl, aryl(C₁-C₆)alkyl,or 2-cyanoethyl:

R₅ is an amino acid, a peptide, or NR_(a) R_(b);

R₇ is hydrogen, halo, hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano,—N(R_(z))C(═O)N(R_(aa))(R_(ab)), —N(R_(z))C(═O)OR_(ac), orNR_(ad)R_(ae);

X is oxy, thio, or methylene;

each R_(a) and R_(b) is independently hydrogen, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, aryl, or aryl(C₁-C₆)alkyl; or R_(a) and R_(b)together with the nitrogen to which they are attached form apyrrolidino, piperidino or morpholino;

each R_(w) is independently hydrogen or (C₁-C₆)alkyl;

R_(x) and R_(y) are each independently hydrogen, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, phenyl, benzyl, phenethyl, or (C₁-C₆)alkanoyl; orR_(x) and R_(y) together with the nitrogen to which they are attachedare pyrrolidino, piperidino or morpholino;

R_(z) is hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl, orphenethyl;

R_(aa) and R_(ab) are each independently hydrogen, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, phenyl, benzyl, or phenethyl; or R_(aa) and R_(ab)together with the nitrogen to which they are attached are pyrrolidino,piperidino or morpholino;

R_(ac) is hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl, orphenethyl;

R_(ad) is hydrogen (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl, orphenethyl;

R_(ae) is hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl, orphenethyl;

wherein any (C₁-C₆)alkyl of R₁-R₇. R_(a), R_(b), R_(w), R_(x), R_(y),R_(z), R_(aa), R_(ab), R_(ac), R_(ad), and R_(ae), is optionallysubstituted with one or more (e.g. 1, 2, 3, or 4) halo, hydroxy,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano, oxo (═O),(C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, (C₃-C₆)cycloalkyl(C₁-C₆)alkyl,(C₁-C₆)alkyl-S—(C₁-C₆)alkyl-, aryl, heteroaryl, aryl(C₁-C₆)alkyl, orheteroaryl(C₁-C₆)alkyl, or NR_(aj)R_(ak); wherein each R_(aj) and R_(ak)is independently hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl,benzyl, or phenethyl;

and wherein any aryl or heteroaryl may optionally be substituted withone or more substituents selected from the group consisting of halo,hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, (C₁-C₆)alkoxy,(C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl, (C₁-C₆)alkanoyloxy,trifluoromethyl, trifluoromethoxy, nitro, cyano, and amino;

or a pharmaceutically acceptable salt thereof;

provided that R₂ and R₃ are each not hydroxy when R₁ is adenine,guanine, cytosine, thymine, or uracil, X is oxy, R₆ is hydrogen, and R₇is hydrogen; and; provided R₁ is not 3-deazaadenine, when R₂ is hydroxy;R₃ is hydroxy; R₄ is hydrogen; R₅ a nitrogen linked radical of formulaIII;

wherein R_(h) is benzyl or 3-indolylmethyl; and R_(j) is methyl; x isoxy, R₆ is hydrogen, and R₇ is hydrogen.

Processes for preparing compounds of formula I are provided as furtherembodiments of the invention and are illustrated by the followingprocedures in which the meanings of the generic radicals are as givenabove unless otherwise qualified.

As illustrated in FIG. 4, a compound of formula I can be prepared from acorresponding compound of formula 43 by removal of the hydroxyprotecting group “pg” (e.g. a silyl protecting group such as atrimethylsilyl group).

The preparation of amino acid phosphoramidates of 3-deaza adenosine and3-deaza aristeromycin is shown in FIG. 1. Direct phosphorylation of DZAand DZAri can be accomplished using phosphorus oxychloride intriethylphosphate, yielding the monophosphates 3 and 4 in 81% and 67%,respectively (Yoshikawa et al., Tetrahedron Lett., 50:5065-5068 (1967);Yoshikawa et al., Bull. Chem. Soc. Jpn., 42:3505-3508 (1969)).Construction of the phosphoramidates was based on a procedure by Moffattand Khorana, in which they describe the dicyclohexylcarbodiimide(DCC)-mediated coupling of adenosine 5′-monophosphate to p-anisidine(Moffatt et al., J. Am. Chem. Soc., 83:649-658 (1961)). Themonophosphates (3 and 4) were then coupled with DCC in refluxingtert-BuOH/H₂O to the carbomethoxy esters of L-phenylalanine andL-tryptophan. The crude product mixtures were purified by reverse phaseHPLC on a C₈ semi-prep column, to give 5-7 in a yield of 8-30%.

As illustrated in FIG. 4, reaction of a nucleoside of formula 38,wherein B is any suitable nucleoside base and R″ and R′″ are eachindependently hydrogen, halo, hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano, or NR_(c)R_(d), witha phosphite of formula 39, wherein each R is independently a suitableradical (e.g. (C₁-C₆)alkyl, aryl, benzyl, or phenethyl, and preferablywherein each R is phenyl), yields an H-phosphate salt of formula 40wherein (M⁺) is a suitable counterion (e.g. triethylammonium);protection of the oxygen in compound 40 with a suitable protecting group“Pg” (e.g. a silyl protecting group such as trimethylsilyl ortert-butyldimethylsilyl) gives a compound of formula 41; treatment withiodine gives a highly reactive compound of formula 42, which canconveniently be reacted directly with an amino acid or peptide to givethe nucleoside phosphoramidate of formula I.

Suitable protecting groups “Pg” are known in the art, for example see T.W. Greene, Protecting Groups In Organic Synthesis; Wiley: New York,1981, and references cited therein. It may also be convenient to protectother functionalities in the intermediate compounds formulae 38-43 withsuitable protecting groups that can be removed at a convenient point inthe synthetic scheme.

In cases where compounds are sufficiently basic or acidic to form stablenontoxic acid or base salts, administration of the compounds as saltsmay be appropriate. Examples of pharmaceutically acceptable salts areorganic acid addition salts formed with acids which form a physiologicalacceptable anion, for example, tosylate, methanesulfonate, acetate,citrate, malonate, tartarate, succinate, benzoate, ascorbate,α-ketoglutarate, and α-glycerophosphate. Suitable inorganic salts mayalso be formed, including hydrochloride, sulfate, nitrate, bicarbonate,and carbonate salts.

Pharmaceutically acceptable salts may be obtained using standardprocedures well known in the art, for example by reacting a sufficientlybasic compound such as an amine with a suitable acid affording aphysiologically acceptable anion. Alkali metal (for example, sodium,potassium or lithium) or alkaline earth metal (for example calcium)salts of carboxylic acids can also be made.

The compounds of the invention can be formulated as pharmaceuticalcompositions and administered to a mammalian host, such as a humanpatient in a variety of forms adapted to the chosen route ofadministration, i.e., orally or parenterally, by intravenous,intramuscular, topical or subcutaneous routes.

Thus, the present compounds may be systemically administered, e.g.,orally, in combination with a pharmaceutically acceptable vehicle suchas an inert diluent or an assimilable edible carrier. They may beenclosed in hard or soft shell gelatin capsules, may be compressed intotablets, or may be incorporated directly with the food of the patient'sdiet. For oral therapeutic administration, the active compound may becombined with one or more excipients and used in the form of ingestibletablets, buccal tablets, troches, capsules, elixirs, suspensions,syrups, wafers, and the like. Such compositions and preparations shouldcontain at least 0.1% of active compound. The percentage of thecompositions and preparations may, of course, be varied and mayconveniently be between about 2 to about 60% of the weight of a givenunit dosage form. The amount of active compound in such therapeuticallyuseful compositions is such that an effective dosage level will beobtained.

The tablets, troches, pills, capsules, and the like may also contain thefollowing: binders such as gum tragacanth, acacia, corn starch orgelatin; excipients such as dicalcium phosphate; a disintegrating agentsuch as corn starch, potato starch, alginic acid and the like; alubricant such as magnesium stearate; and a sweetening agent such assucrose, fructose, lactose or aspartame or a flavoring agent such aspeppermint, oil of wintergreen, or cherry flavoring may be added. Whenthe unit dosage form is a capsule, it may contain, in addition tomaterials of the above type, a liquid carrier, such as a vegetable oilor a polyethylene glycol. Various other materials may be present ascoatings or to otherwise modify the physical form of the solid unitdosage form. For instance, tablets, pills, or capsules may be coatedwith gelatin, wax, shellac or sugar and the like. A syrup or elixir maycontain the active compound, sucrose or fructose as a sweetening agent,methyl and propylparabens as preservatives, a dye and flavoring such ascherry or orange flavor. Of course, any material used in preparing anyunit dosage form should be pharmaceutically acceptable and substantiallynon-toxic in the amounts employed. In addition, the active compound maybe incorporated into sustained-release preparations and devices.

The active compound may also be administered intravenously orintraperitoneally by infusion or injection. Solutions of the activecompound or its salts can be prepared in water, optionally mixed with anontoxic surfactant. Dispersions can also be prepared in glycerol,liquid polyethylene glycols, triacetin, and mixtures thereof and inoils. Under ordinary conditions of storage and use, these preparationscontain a preservative to prevent the growth of microorganisms.

The pharmaceutical dosage forms suitable for injection or infusion caninclude sterile aqueous solutions or dispersions or sterile powderscomprising the active ingredient which are adapted for theextemporaneous preparation of sterile injectable or infusible solutionsor dispersions, optionally encapsulated in liposomes. In all cases, theultimate dosage form must be sterile, fluid and stable under theconditions of manufacture and storage. The liquid carrier or vehicle canbe a solvent or liquid dispersion medium comprising, for example, water,ethanol, a polyol (for example, glycerol propylene glycol, liquidpolyethylene glycols, and the like), vegetable oils, nontoxic glycerylesters, and suitable mixtures thereof. The proper fluidity can bemaintained, for example, by the formation of liposomes, by themaintenance of the required particle size in the case of dispersions orby the use of surfactants. The prevention of the action ofmicroorganisms can be brought about by various antibacterial andantifungal agents, for example, parabens, chlorobutanol, phenol, sorbicacid, thimerosal, and the like. In many cases, it will be preferable toinclude isotonic agents, for example, sugars, buffers or sodiumchloride. Prolonged absorption of the injectable compositions can bebrought about by the use in the compositions of agents delayingabsorption, for example, aluminum monostearate and gelatin.

Sterile injectable solutions are prepared by incorporating the activecompound in the required amount in the appropriate solvent with variousof the other ingredients enumerated above, as required, followed byfilter sterilization. In the case of sterile powders for the preparationof sterile injectable solutions, the preferred methods of preparationare vacuum drying and the freeze drying techniques, which yield a powderof the active ingredient plus any additional desired ingredient presentin the previously sterile-filtered solutions.

For topical administration, the present compounds may be applied in pureform. i.e., when they are liquids. However, it will generally bedesirable to administer them to the skin as compositions orformulations, in combination with a dermatologically acceptable carrier,which may be a solid or a liquid.

Useful solid carriers include finely divided solids such as talc, clay,microcrystalline cellulose, silica, alumina and the like. Useful liquidcarriers include water, alcohols or glycols or water-alcohol/glycolblends, in which the present compounds can be dissolved or dispersed ateffective levels, optionally with the aid of non-toxic surfactants.Adjuvants such as fragrances and additional antimicrobial agents can beadded to optimize the properties for a given use. The resultant liquidcompositions can be applied from absorbent pads, used to impregnatebandages and other dressings, or sprayed onto the affected area usingpump-type or aerosol sprayers.

Thickeners such as synthetic polymers, fatty acids, fatty acid salts andesters, fatty alcohols, modified celluloses or modified mineralmaterials can also be employed with liquid carriers to form spreadablepastes, gels, ointments, soaps, and the like, for application directlyto the skin of the user.

Examples of useful dermatological compositions which can be used todeliver the compounds of formula I to the skin are known to the art; forexample, see Jacquet et al. (U.S. Pat. No. 4,608,392), Geria (U.S. Pat.No. 4,992,478), Smith et al. (U.S. Pat. No. 4,559,157) and Wortzman(U.S. Pat. No. 4,820,508).

Useful dosages of the compounds of formula I can be determined bycomparing their in vitro activity, and in vivo activity in animalmodels. Methods for the extrapolation of effective dosages in mice, andother animals, to humans are known to the art; for example, see U.S.Pat. No. 4,938,949.

Generally, the concentration of the compound(s) of formula I in a liquidcomposition, such as a lotion, will be from about 0.1-25 wt-%,preferably from about 0.5-10 wt-%. The concentration in a semi-solid orsolid composition such as a gel or a powder will be about 0.1-5 wt-%,preferably about 0.5-2.5 wt-%.

The amount of the compound, or an active salt or derivative thereof,required for use in treatment will vary not only with the particularsalt selected but also with the route of administration, the nature ofthe condition being treated and the age and condition of the patient andwill be ultimately at the discretion of the attendant physician orclinician.

In general, however, a suitable dose will be in the range of from about0.5 to about 100 mg/kg, e.g., from about 10 to about 75 mg/kg of bodyweight per day, such as 3 to about 50 mg per kilogram body weight of therecipient per day, preferably in the range of 6 to 90 mg/kg/day, mostpreferably in the range of 15 to 60 mg/kg/day.

The compound is conveniently administered in unit dosage form; forexample, containing 5 to 1000 mg, conveniently 10 to 750 mg, mostconveniently, 50 to 500 mg of active ingredient per unit dosage form.

Ideally, the active ingredient should be administered to achieve peakplasma concentrations of the active compound of from about 0.5 to about75 μM, preferably, about 1 to 50 M, most preferably, about 2 to about 30μM. This may be achieved, for example, by the intravenous injection of a0.05 to 5% solution of the active ingredient, optionally in saline, ororally administered as a bolus containing about 1-100 mg of the activeingredient. Desirable blood levels may be maintained by continuousinfusion to provide about 0.01-5.0 mg/kg/hr or by intermittent infusionscontaining about 0.4-15 mg/kg of the active ingredient(s).

The desired dose may conveniently be presented in a single dose or asdivided doses administered at appropriate intervals, for example, astwo, three, four or more sub-doses per day. The sub-dose itself may befurther divided, e.g., into a number of discrete loosely spacedadministrations; such as multiple inhalations from an insufflator or byapplication of a plurality of drops into the eye.

Generally the phosphoramidate compounds of the invention are less toxicand have greater anti-cancer or anti-viral activity than thecorresponding parent nucleosides. Additionally, phosphoramidates of theinvention may be more soluable, more stable, have greater half-lives invivo, or have better tissue distribution than the corresponding parentnucleosides.

The compounds of the invention can generally be prepared usingprocedures similar to those described in U.S. Pat. No. 6,475,985.

The ability of a compound of the invention to act as an antiviral agentmay be determined using pharmacological models which are well known tothe art, or using Test A or B described below.

Test A.

The antiviral activity of representative compounds of the invention wasdetermined with matched HIV-1 isolates and a laboratory HIV-1 strain aspreviously described (D. L Mayers et al., Proc. Natl. Acad. Sci., USA,1995, 92, 215-219; and C. R. Wagner et al., Bioorganic and MedicinalChemistry Letters, 1995, 5, 1819-1824).

Test B

The antiviral properties of compounds of the invention can also bedetermined in PBMCs using a procedure similar to that described by E. I.McIntee, et al. J. Med. Chem., 1997, 40, 3323-3331.

The invention will now be illustrated by the following non-limitingExamples, wherein unless otherwise stated: NMR (¹H and ³¹P) spectra wererecorded on Varian VXR-300 and GE Omega-300 spectrometers; an externalstandard of 85% H₃PO₄ was used for all ³¹P-NMR spectra; ESI mass spectrawere obtained on a Finnigan TSQ 7000 mass spectrometer; analytical TLCwas performed on Analtech Silica Gel GHLF (0.25 mm) or Machery-NagelPolygram Sil G/UV₂₅₄ (0.2 mm) plates; concentration under reducedpressure refers to solvent removal on a Buchi rotary evaporator; highvacuum refers to <10⁻² psi attained with a DuoSeal mechanical pump; allsolvents were reagent grade and used as received unless noted; and3-deaza adenosine and 3-deaza aristeromycin (which can be prepared usingprocedures similar to those described by J. A. Montgomery, et al. J.Med. Chem., 1982, 25, 626-629; and J. A. Montgomery, et al. Heterocycl.Chem., 1977, 14, 195, were obtained from Walter Reed Army Institute ofResearch, Wash. D.C.

Test C

The anti-cancer properties of the compounds of the invention can beevaluated using the following assay.

CCRF-CEM cells were grown in medium containing RPMI 1640 supplementedwith 10% heat-inactivated fetal bovine serum, penicillin (124 units/mlof medium) and streptomycin (0.125 mg/ml of medium). A stock solution of10⁵ cells was made using Trypan Blue Dye Exclusion Method as a means ofcounting the cells. The following concentrations of test compounds weremade: 250, 200, 100, 10, 1, 0.1, 0.01 and 0.001 μM. The cell stock (50μl, 5×10⁴ cells) was incubated with 50 μl of each of the compounds intriplicate in a 96-well plate. The cells were incubated with thecompound at 37° C. in a 10% CO₂-90% air environment for 48 hr. Anegative control was also done where the cells were incubated indrug-free medium.

Cell viability was determined by adding 20 μl of MTS reagent andincubating the cells for 4 hr after which the absorbance was found at490 nm. Data for representative compounds is shown below.

Compound IC50 (μM) 115  11 ± 14 113 229 ± 68 114 23 ± 7 Ara-A 384 ± 34

Example 1

Representative compounds of the invention can be prepared using aprocedure similar to the one below.

Coupling of Ara-A 5′-monophosphate (1 eq) and amino acid methyl ester(1.1 eq) was carried out using EDC.HCl (5 eq) and N-methyl-morpholine (5eq) buffered at pH=6.94. The reaction was monitored by silica TLC(5:3:0.5 CHCl₃:MeOH:H₂O). After completion, the reaction wasconcentrated and purified via silica column. The Ara-A phosphoramidatemorpholine salt was passed through a Na+ exchange column to generate thesodium salt.

Example 2

Representative compounds of the invention can be prepared using aprocedure similar to those described by T. Chou et al., The Journal ofBiological Chemistry, 2005, 280, 15356-15361. The following compoundswere prepared using such a procedure.

Com- Nucle- Theoretical Error pound otide Amino Acid mass [M − H]⁻ (ppm)100 AMP L-TrpCOOMe 546.1508 546.1503 −0.9 101 AMP L-TrpCONMe 547.1824547.1851 4.9 102 AMP L-TrpCONH₂ 533.1668 533.1669 0.3 103 AMP D-TrpCOOMe546.1508 546.1513 1.0 104 AMP Tryptamine 488.1447 488.148 6.7 105 GMPL-TrpCOOMe 562.1451 562.1468 3.0 106 GMP L-TrpCONMe 563.1773 563.18137.1 107 GMP L-TrpCONH₂ 547.146 547.1444 −3.0 108 GMP D-TrpCOOMe 562.1451562.1462 1.9 109 GMP Tryptamine 504.1397 504.140 0.7 110 IMP L-TrpCOOMe547.1342 547.1351 1.6 111 IMP D-TrpCOOMe 547.1342 547.1335 −1.4 112 IMPTryptamine 489.1288 489.1279 −1.8 113 Ara-AMP L-TrpCOOMe 546.1508546.1496 −2.1 114 Ara-AMP D-TrpCOOMe 546.1508 546.1503 −0.9 115 Ara-AMPTryptamine 488.1447 488.1422 −5.2 116 TMP L-TrpCONMe 520.1597 520.1592−1.0 117 TMP D-TrpCOOMe 521.1437 521.1426 −2.2 118 TMP Tryptamine463.1383 463.1396 2.9 119 CMP D-TrpCOOMe 522.139 522.1399 1.7 120 CMPL-TrpCONH₂ 507.1393 507.1399 1.1 121 CMP Tryptamine 464.1335 464.13350.0 122 UMP D-TrpCOOMe 523.123 523.124 1.9 123 UMP Tryptamine 465.1175465.1174 −0.3 A = Adenosine, G = Guanosine, I = inosine, T = thymidine,U = uridine, Ara-A = 9-beta-D-arabinofuranosyladenosine Trp = tryptophanCOOME = carbomethoxy ester, CONMe = methyl amide *Most of compounds wereanalyzed in negative mode except compounds 101, 102, and 106.

Example 3

The following illustrate representative pharmaceutical dosage forms,containing a compound of formula I (‘Compound X’), for therapeutic orprophylactic use in humans.

(i) Tablet 1 mg/tablet ‘Compound X’ 100.0 Lactose 77.5 Povidone 15.0Croscarmellose sodium 12.0 Microcrystalline cellulose 92.5 Magnesiumstearate 3.0 300.0

(ii) Tablet 2 mg/tablet ‘Compound X’ 20.0 Microcrystalline cellulose410.0 Starch 50.0 Sodium starch glycolate 15.0 Magnesium stearate 5.0500.0

(iii) Capsule mg/capsule ‘Compound X’ 10.0 Colloidal silicon dioxide 1.5Lactose 465.5 Pregelatinized starch 120.0 Magnesium stearate 3.0 600.0

(iv) Injection 1 (1 mg/ml) mg/ml ‘Compound X’ (free acid form) 1.0Dibasic sodium phosphate 12.0  Monobasic sodium phosphate 0.7 Sodiumchloride 4.5 1.0N Sodium hydroxide solution q.s. (pH adjustment to7.0-7.5) Water for injection q.s. ad 1 mL

(v) Injection 2 (10 mg/ml) mg/ml ‘Compound X’ (free acid form) 10.0 Monobasic sodium phosphate 0.3 Dibasic sodium phosphate 1.1 Polyethyleneglycol 400 200.0  01N Sodium hydroxide solution q.s. (pH adjustment to7.0-7.5) Water for injection q.s. ad 1 mL

(vi) Aerosol mg/can ‘Compound X’ 20.0 Oleic acid 10.0Trichloromonofluoromethane 5,000.0 Dichlorodifluoromethane 10,000.0Dichlorotetrafluoroethane 5,000.0The above formulations may be obtained by conventional procedures wellknown in the pharmaceutical art.

All publications, patents, and patent documents are incorporated byreference herein, as though individually incorporated by reference. Theinvention has been described with reference to various specific andpreferred embodiments and techniques. However, it should be understoodthat many variations and modifications may be made while remainingwithin the spirit and scope of the invention.

What is claimed is:
 1. A compound of formula I:

wherein: R₁ is adenine, guanine, cytosine, thymine, 3-deazaadenine, oruracil, optionally substituted by 1, 2, or 3 U; wherein each U isindependently halo, hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, hydroxy(C₁-C₆)alkyl,—(CH₂)₁₋₄P(═O)(OR_(w))₂ aryl, aryl(C₁-C₆)alkyl, or NR_(x)R_(y); R₂ andR₆ are each independently hydrogen, halo, hydroxy, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, (C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano,—N(R_(z))C(═O)N(R_(aa))(R_(ab)), —N(R_(z))C(═O)OR_(ac), orNR_(ad)R_(ae), provided that one of R₂ and R₆ is hydroxy halo,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, trifluoromethyl, cyano, orNR_(ad)R_(ae); R₃ is hydrogen, halo, hydroxy, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, (C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano,—N(R_(z))C(═O)N(R_(aa))(R_(ab)), —N(R_(z))C(═O)OR_(ac), orNR_(ad)R_(ae); R₄ is hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, aryl,aryl(C₁-C₆)alkyl, or 2-cyanoethyl; R₅ is an amino acid, a peptide, orNR_(a) R_(b); R₇ is hydrogen, halo, hydroxy, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, (C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano,—N(R_(z))C(═O)N(R_(aa))(R_(ab)), —N(R_(z))C(═O)OR_(ac), orNR_(ad)R_(ae); X is oxy, thio, or methylene; each R_(a) and R_(b) isindependently hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, aryl, or Het;or R_(a) and R_(b) together with the nitrogen to which they are attachedform a nitrogen-linked Het; each R_(w) is independently hydrogen or(C₁-C₆)alkyl; R_(x) and R_(y) are each independently hydrogen,(C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl, phenethyl, or(C₁-C₆)alkanoyl; or R_(x) and R_(y) together with the nitrogen to whichthey are attached are pyrrolidino, piperidino or morpholino; R_(z) ishydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl, or phenethyl;R_(aa) and R_(ab) are each independently hydrogen, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, phenyl, benzyl, or phenethyl; or R_(aa) and R_(ab)together with the nitrogen to which they are attached are pyrrolidino,piperidino or morpholino; R_(ac) is hydrogen, (C₁-C₆)alkyl,(C₃-C₆)cycloalkyl, phenyl, benzyl, or phenethyl; R_(ad) is hydrogen(C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl, or phenethyl; R_(ae) ishydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl, or phenethyl;wherein any (C₁-C₆)alkyl of R₁-R₇, R_(a), R_(b), R_(w), R_(x), R_(y),R_(z), R_(aa), R_(ab), R_(ac), R_(ad), and R_(ae) is optionallysubstituted with one or more (e.g. 1, 2, 3, or 4) halo, hydroxy,(C₁-C₆)alkoxy, (C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl,(C₁-C₆)alkanoyloxy, trifluoromethyl, azido, cyano, oxo (═O),(C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, (C₃-C₆)cycloalkyl(C₁-C₆)alkyl,(C₁-C₆)alkyl-S—(C₁-C₆)alkyl-, aryl, Het, aryl(C₁-C₆)alkyl, orHet(C₁-C₆)alkyl, or NR_(aj)R_(ak); wherein each R_(aj) and R_(ak) isindependently hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, phenyl, benzyl,or phenethyl; and wherein any aryl or Het may optionally be substitutedwith one or more substituents selected from the group consisting ofhalo, hydroxy, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, (C₁-C₆)alkoxy,(C₃-C₆)cycloalkyloxy, (C₁-C₆)alkanoyl, (C₁-C₆)alkanoyloxy,trifluoromethyl, trifluoromethoxy, nitro, cyano, and amino; or apharmaceutically acceptable salt thereof; provided that R₂ and R₃ areeach not hydroxy when R₁ is adenine, guanine, cytosine, thymine, oruracil, X is oxy, R₅ is an amino acid or a peptide; R₆ is hydrogen, andR₇ is hydrogen; and; provided R₁ is not 3-deazaadenine, when R₂ ishydroxy; R₃ is hydroxy; R₄ is hydrogen; R₅ a nitrogen linked radical offormula III;

wherein R_(h) is benzyl or 3-indolylmethyl; and R_(j) is methyl; x isoxy, R₆ is hydrogen, and R₇ is hydrogen.